1. Field
Example embodiments relate to an optoelectronic device, and an image sensor and/or an electronic device including the same.
2. Description of Related Art
An optoelectronic device is a device in which a charge exchange occurs between an electrode and a photoelectric conversion layer by using holes or electrons.
An optoelectronic device may be classified based on its driving principles. A first type of optoelectronic device may be driven as follows: excitons are generated in a photoelectric conversion layer by photons from an external light source; the excitons are separated into electrons and holes; and the electrons and holes are transferred to different electrodes as a current source (voltage source). A second type of optoelectronic device may be driven as follows: a voltage or a current is applied to at least two electrodes to inject holes and/or electrons into a photoelectric conversion layer positioned at an interface of the electrodes, and the device is driven by the injected electrons and holes.
The optoelectronic device may have a structure in which a photoelectric conversion layer including a functional inorganic or organic material is between an anode and a cathode. The optoelectronic device may include a buffer layer (e.g. a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL)) between an anode and a photoelectric conversion layer or a cathode and a photoelectric conversion layer, in order to improve efficiency and stability.
An organic optoelectronic device including a photoelectric conversion layer including an organic material may have relatively low external quantum efficiency in a visible light region and a relatively high dark current due to internal impurities in the organic material compared with an inorganic optoelectronic device including an inorganic oxide. The high dark current may increase the leakage current of the organic optoelectronic device. The increased leakage current may deteriorate the sensitivity of the organic optoelectronic device as well as accuracy of the external quantum efficiency converted from a photocurrent during the photoreaction and increases noise signals.
Accordingly, development of an optoelectronic device capable of decreasing the dark current is needed.